Implications of Conical Flow for Laminar Wing Design and Analysis

Kurzfassung

In this work a method based on sectional conical wings is presented which allows the analysis and design of airfoil sections for swept tapered wings with a computational effort which is slightly higher than a 2D computation. Navier-Stokes analysis and re-design examples using the sectional conical wing approximation are given. They show that pressure distribution, boundary layer stability analysis and designed airfoil geometry compare better with the 3D swept tapered wing solution than results obtained using solutions based on infinite swept wing theory. In the second part of the work the transversal flow incompressible solution for a conical wing with circular airfoil section is given. For small cone angles sectional conical solutions are obtained. The crossflow instability significant stagnation line velocity is obtained. It corresponds to an effective leading edge sweep angle which is twice the cone angle. An extension of this equation is obtained and verified for usual transport aircraft 3D wings by parametric studies varying airfoil section, root to tip thickness and leading edge radius.